1. Field of the Invention
The present invention relates to an axial gap type generator that is mounted on an engine, and more particularly, to an axial gap type generator in which the precision in positioning stator cores is increased.
2. Description of the Related Art
For general-purpose engines or the like for industrial use include instances where, for example, there is known a configuration in which a generator is connected to one end of a crankshaft protruding out of an engine main body.
For instance, a technique disclosed in Japanese Unexamined Patent Application Publication (JP-A) No. H10-4650 provides magnets for power generation at a flywheel that is fixed to the crankshaft end of a motorcycle engine, and coils for power generation, the coils being fixed to the engine, at sites that oppose the magnets in the radial direction.
Furthermore, in recent years, the use of an axial gap type generator has been proposed for compact generator configurations. In the axial gap type generator, stator cores that are fixed to the engine and are provided with power generation coils, and rotor yokes that are provided with magnets for power generation and rotate together with a crankshaft are disposed opposing one another in the center axis direction of the crankshaft.
For instance, Japanese Unexamined Patent Application Publication No. 2009-216014 discloses an axial gap type generator in which a stator core that is fixed to an engine is disposed in spacing between a pair of rotor yokes that are disposed, protruding from a crankshaft, towards the outer diameter side, and that are spaced apart from each other in the axial direction.
Also, in an axial gap type generator disclosed JP-A No. 2010-038006, protrusions that are integrally formed with a stator are directly connected with a support member on the side of an engine, thereby enhancing the positioning precision of a stator core with respect to the engine.
In axial gap type generators such as those described above, the efficiency of the generator depends on the axial-direction gap between a stator core and a rotor yoke. Therefore, it is important to set the gap with good precision.
In the case where a pair of stator cores that oppose each other across a rotor yoke is fixed by way of a plurality of interposed parts, however, there arises the problem of increased variability in the stator core spacing, due to the unavoidable accumulation of dimensional tolerances in the manufacture of the parts.